Road roller



May 9, 1967 K. H. SCHWAMBORN ETAL 3,318,210

ROAD ROLLER Filed March 4, 1965 2 Sheets-Sheet 1 Fig. I

lnventorg KARL HEIA/Z SLHWHMBURN FHUL OTTO sum/cu 7' WWI/WWW ATTORNEY$ May 9, 1967 K. H. SCHWAMBORN ETAL 3,318,210

ROAD ROLLER Filed March 4., 1965 2 Sheets-Sheet 2 Fig. 3

4 Inventors AHRL HE/NZ SCHWHMBORN ,6 PAUL OTTO SCHHICH -TT Q Y United States Patent 3,318,210 ROAD ROLLER Karl Heinz Schwamborn, Boppard (Rhine), and Paul Otto Schaich, Munich, Germany, assignors to Bomag Bopparder Maschinenbaugesellschaft m.b.H., Boppard, Germany Filed Mar. 4, 1965, Ser. No. 437,023

Claims priority, application Germany, Mar. 11, 1964,

4 Claims. (CI. 94-50) This invention relates in general to street paving vehicles or so-called road rollers, and in particular to a new and useful road roller having a roller assembly for steering which includes two drums or rollers concentrically arranged and laterally aligned which may be driven in each rotative direction at identical or varied speeds.

The invention particularly concerns a steerable road roller or street paving vehicle, preferably a double vibration road roller, with two roller drums or drum sets arranged in series, of which at least one can be driven by a motor selectively in both directions. Smaller rollers of this type are provided with a steering fork and a pole with which the roller is guided by hand. But steering by means of a pole requires great strength with driven undivided roller drums.

A feature of the invention is that one roller drum, which may be driven, is undivided, while the other driven roller drum is divided into two juxtaposed laterally divided par tial drums which can 'be driven at will at different speeds under the control of a simple hand control. Depending on the selected hand control, the drums may be driven at the same or different speeds to steer the vehicle. The control may be actuated by a person walking alongside the device without expending too much energy.

In a preferred arrangement, one of the forward or rear rollers or roller sets is divided into two juxtaposed partial drums, each driven over a clutch limiting the torque, which can be braked individually, at will.

Accordingly, an object of the invention is to provide a mechanical steering aid for road rollers which can be operated by a person walking alongside the device as well as by a person riding on the steam roller.

A further object of the invention is to provide a street paving vehicle including at least one roller set which comprises at least two laterally aligned and concentrically arranged drums which are driven preferably in each rotational direction and with means for varying the rotational speed of one or both for effecting a change in the direction of movement of the vehicle and preferably with a control for the speed varying means which may be operated in a simple manner either by an operator on the vehicle or one walking alongside.

A further object of the invention is to provide a road roller which is simple in design, rugged in construction, and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

In the drawings:

FIG. 1 is a top plan view of a road roller constructed in accordance with the invention;

FIG. 2 is a section taken along the line 2-2 of FIG. 1;

FIG. 3 is a side elevational view of another embodiment of road roller; and

FIG. 4 is a section taken along the line 44 of FIG. 3.

Referring to the drawings in particular, the road roller represented in FIGS. 1 and 2 is provided with a frame 1, in which are arranged first and second longitudinally spaced roller means comprising a roller drum 2 extending over the entire width of the frame and two juxtaposed laterally aligned drums or partial drums: 3 and 4, each supported by means of ball bearings 5 on a hollow shaft or tube 6. The tube 6 is rotatably mounted in the frame 1 by means of ball bearings 7 at each side. The support for the partial drums 3 and 4 which is illustrated in FIG. 1 is of the same type for the drum 2.

Each tube 6 carries at its projecting end a fixed chain wheel or sprocket 8 which is driven by means of a chain 9 (FIG. 1) by a hydraulic motor 10. The hydraulic motor 10 is connected over pipes indicated by broken lines with the valves of a valve block 11, which is connected by pipes 40 and 42 to a hydraulic pump 12, which is driven by a motor such as a diesel engine 13 arranged on the frame 1. In each tube 6 is arranged an imbalance shaft 14 which is rotatably supported on ball bearings 15 (FIG. 2). On the end of the imbalance shaft 14 projecting to the outside is arranged a pulley or sprocket 16, which is driven by the diesel engine 13 over a belt or chain drive 17.

Clutch means such as an entrainer disc or clutch plate 18 is affixed to the tube 6 for rotation therewith (FIG. 2). On both sides of the entrainer disc 18 there are provided close to the edge a number of recesses for balls 19, of which only four balls are shown in FIG. 2. Each partial drum carries on the front wall facing the entrainer disc a ring 20 with recesses corresponding to the balls. The balls 19 are held in the position illustrated in FIG. 2 by springs (not represented), which are provided either in the entrainer disc 18 or the ring 20.

The space surrounding the entrainer disc between the facing front walls of the two partial drums 3 and 4 is sealed by a jacket 21 with elastic edges arranged on the entrainer disc in order to prevent dirt from getting into the entrainer disc space through the gap between the two partial drums.

Each partial drum 3 or 4 is equipped on the outer front wall with a brake disc 22, which is associated with a mechanically or hydraulically operated brake shoe arrangement 23.

The double-vibration steam roller represented in FIGS. 1 and 2 is equipped with a fork 24 and a pole25. In the operating range of the fork 24 is provided a control wheel 26 which is connected to the valve block for operating the drive of the tube 6. The pole 25 carries also in the operating range adjusting levers (not represent-ed) which can act on the two brake shoe arrangements 23 over control elements, for example, Bowden wires 27 and 28.

During the driving, the entrainer disc 18 acts with the balls 19 and the rings 20 as a clutch which effects the same speed of the entrainer disc and of the partial drums 3 and 4. Depending on the drive of the tube 6 as adjusted by the control wheel 26, the roller advances with a certain speed straight forward. It is clear that the drum 2 can also be driven in a corresponding manner. If the roller is to deviate from the straight direction, the operator brakes a selected drum 3 or 4 by operating the brake shoe arrangement 23 on the side to which the roller is to turn. When braking one partial drum, the ball clutch means or clutch plate 18 associated with this partial drum is released and acts as an overload clutch. When either roller is braked, the braking force overrides the lateral force of the springs acting on the rollers 19 so that the braked roller becomes disengaged from the driving clutch plate 18. If one partial drum 3 or 4 has been disengaged, the other partial drum drives and effects a turning or the change of direction of the steam roller.

In the embodiment represented in FIGS. 3 and 4, there is provided different clutch means comprising an entrainer disc 18' with a plurality of compensation wheels or bevel gears 30, which engage a corresponding bevel gearing 29 and 31 of the two partial drums 2' and 4'. A differential effect permitting rotation of the drums 3' and 4 is provided by the gears 29, 30 and 31, and thus steering is achieved during the braking of one or the other partial drum.

The embodiment of FIGS. 3 and 4 comprises a doublevibration road roller having a steering wheel 32 for the riding operator to influence one or the other brake shoe arrangement 23 over mechanical or hydraulic control means. The rollers 2, 3' and 4' are driven in this embodiment over a gearing 33 instead of chains or belts. The brake shoe arrangement 23 advantageously comprises disc brakes with hydrostatic brake reinforcement, which bear on the frame.

The drum 2 advantageously extends over the entire width of the roller but may have a length different from the width. Preferably, however, the drum 2 is arranged symmetrically to the partial drums 3' and 4 in order to bridge over the unavoidable gap between the two partial drums.

While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A steerable road roller comprising a frame, a first roller drum rotatably supported by said frame adjacent one end thereof, a second roller drum assembly rotatably supported by said frame adjacent the opposite end thereof, said second roller drum assembly including a drive axle, first and second partial drums arranged side by side with a slight spacing therebetween and rotatably supported on said axle and together being substantially the same width as said first roller drum, a clutch between said first and second partial drums including a driving part carried on said drive axle and a slippable part carried by respective ones of said first and second partial drums for rotating said partial drums with said axle and for permitting slippage and non-rotation of one of said first and second partial drums, a sealing jacket disposed around said clutch and substantially bridging the slight spacing between said first and second partial drums, means connected to said tubular axle to rotate said axle, and brake means for selectively braking a respective one of said first and second partial drums.

2. A steerable road roller according to claim 1, including an imbalanced shaft rotatably mounted within said axle, said axle tbeing tubular, and means for rotating said imbalanced shaft.

3. A steerable road roller according to claim 1, wherein said clutch includes a plate secured to said axle and rotatable therewith, and a ring member carried by each of said partial drums and slippingly engaged with said plate.

4. A steerable road roller according to claim 1, wherein said clutch includes a double bevel gear secured to said axle and rotatable therewith, and a bevel gear carried by each of said drums in meshing engagement with said double bevel gear.

References Cited by the Examiner UNITED STATES PATENTS 2,078,900 4/1937 Biles 94-50 2,352,593 7/1944 Allin --6.2 2,549,182 4/ 1951 Ekenstam 94-5O 2,757,373 7/1956 Marrie 180-62 3,015,997 1/1962 Seaman 94-50 FOREIGN PATENTS 889,747 2/ 1962 Great Britain.

JACOB L. NACKENOFF, Primary Examiner. 

1. A STEERABLE ROAD ROLLER COMPRISING A FRAME, A FIRST ROLLER DRUM ROTATABLY SUPPORTED BY SAID FRAME ADJACENT ONE END THEREOF, A SECOND ROLLER DRUM ASSEMBLY ROTATABLY SUPPORTED BY SAID FRAME ADJACENT THE OPPOSITE END THEREOF, SAID SECOND ROLLER DRUM ASSEMBLY INCLUDING A DRIVE AXLE, FIRST AND SECOND PARTIAL DRUMS ARRANGED SIDE BY SIDE WITH A SLIGHT SPACING THEREBETWEEN AND ROTATABLY SUPPORTED ON SAID AXLE AND TOGETHER BEING SUBSTANTIALLY THE SAME WIDTH AS SAID FIRST ROLLER DRUM, A CLUTCH BETWEEN SAID FIRST AND SECOND PARTIAL DRUMS INCLUDING A DRIVING PART CARRIED ON SAID DRIVE AXLE AND A SLIPPABLE PART CARRIED BY RESPECTIVE ONES OF SAID FIRST AND SECOND PARTIAL DRUMS FOR ROTATING SAID PARTIAL DRUMS WITH SAID AXLE AND FOR PERMITTING SLIPPAGE AND NON-ROTATION OF ONE OF SAID FIRST AND SECOND PARTIAL DRUMS, A SEALING JACKET DISPOSED AROUND SAID CLUTCH AND SUBSTANTIALLY BRIDGING THE SLIGHT SPACING BETWEEN SAID FIRST AND SECOND PARTIAL DRUMS, MEANS CONNECTED TO SAID TUBULAR AXLE TO ROTATE SAID AXLE, AND BRAKE MEANS FOR SELECTIVELY BRAKING A RESPECTIVE ONE OF SAID FIRST AND SECOND PARTIAL DRUMS. 